I am writing to this forum because I had unlocked almost everything there is to unlock in (the free version of) desktop dungeons. However, I started it up just a few minutes ago to find that almost all of my progress had been deleted. I had unlocked ranked play, as well as the gorgon and half-dragon classes, and the goblin and orc races, etc. And now all of my progress is gone. Only the berserker remains unlocked, for some reason that I cannot fathom.
And no, I did not switch to a different username (I checked that).
This game is fun enough that I would buy a paid version, but not now that I know it will spontaneously erase all of my progress.